Vitamin B12 is essential for the function of bone marrow, the central nervous system, and the gastrointestinal tract. Absorption from the gastrointestinal tract is a complex process which culminates in active uptake in the distal ileum. Patients that have had distal ileum resections require vitamin B12 supplementation via an alternative route, particularly in monthly intramuscular injections, to prevent deficiency of this essential nutrient. Intranasal administration of vitamin B12 has previously been shown to be a viable alternative to sustain adequate serum concentrations in adults. Use of intranasally applied vitamin B12 in children and dosage requirements is not well studied in children.